Apparatus for continuous



I5 Sheets-Sheet` l Dec. 3, 1946. J. R. osUNA APPARATUS FOR CONTINUOUSCLARIFICATION Original Filed July 10, 1941 f/v VEN TOR.

A T To /efvfys l2/ /20 glA Dec. 3, 1946.

.1. R. `osLJNA APPARATUS FOR CONTINUOUS CLARIFICATION original FiledJuly 1o, 1941' s sheets-Sheet 2 ,a vjNvfNrok. l

Dec. 3, 1946. J. R. osUNA Re 22,814

` APPARATUS FOR CONTINUOUS CLARIFICATION Original Filed July` 10, 1941 3Sheets-Sheet 3 A T TORNEYS Reissued Dec. 3, 1946 ernannt-:Us FORCONTINUOUS CLARTFICATION .lose Ramn Gsuna, Marianao, Cuba @riginal No.2,307,154, dated January 5, 1943, Se-

rial No. 401,824, July 10, 1941. Application for reissue December 3,1943, Serial No. 512,761.

In Cuba July 30, 1940 7 Claims. l

The method heretofore employed in the man facture of sugar andparticularly in the sugar refining operation, consists in subjecting thesyrups formed by dissolution of washed or affinated raw sugar to apurification process which is carried out as follows: The washed orailinated sugar is dissolved in water in tanks provided with agitatorsto form a syrup with a density of 60 Brix, and the syrup obtained ispurined by treatment with chemical. agents and heat. The solutions thustreated are discharged into open tanks (defecatcrs) to be subjected toclaritication by decantation. The number of defecators or tanks isdependent upon the amount oi material to be treated in 24 hours and uponthe time required for obtaining the clariiioation in each tank. In thecase of dense solutions which are the ones being usually treated atsugar reiineries, the average time required for decantation varies from45 to 60 minutes and sometimes more, depending upon the liquid level,density and temperature.

The processes heretofore employed require the temperature to be raisedsometimes even to above 216 F. in order that the floccules formed mayrapidly ascend to the liquid surface and properly separate after theyhave overcome the weight of the liquid upon them. It is just in thisstage that the so-called manufacturing losses occur,

which are caused by the heat affecting the sucrose and tending to invertit thereby yielding a greater percentage of molasses to the factory;heat also causing the liquid to become darkened on account of thecandied condition of sucrose, and the use of additional decoloringagents being required in a further decoloring operation in order toobtain a No. 1 liquor from which reiined sugar is obtained as the finalproduct.

vbetween 2e" andG, a temperature diierence. oi

3 C. or more below the corresponding vacuum temperature, being used.Said 3 C. temperature difference is used for the purpose of preventingthe liquid from boiling for it is a well known fact that every liquidattains a boiling point according to the pressure acting upon same.

The advantages possessed by my clarification method and apparatus are,in the case of refinery syrups, that these can be clarified at a lowertemperature than is at present required, without danger of increasingthe darkness of color, and an increase of velocity is attained whichpermits to treat a larger quantity of material in the same period oftime with smaller tanks and in a shorter period of treatment, whereupona considerable reduction is obtained in the losses on in- 2 versionwhich occur under the methods at present known.

The invention is described with reference to the figures of theaccompanying drawings, of which:

Fig. l is a diametral vertical sectional view of a continuous clarifierand attachments thereof for carrying out the clarification method beingIthe vsubject-matter of this invention.

Fig. 2 is a top plan view of same.

Fig. 3 is a longitudinal vertical sectional view of the level regulatoron line 3 3 of Fig. 2.

Fig. i is a fragmentary outer elevational view of the tray forming theupper chamber of the clarifier'.

Fig. 5 is a fragmentary top plan View of the same tray.

Fig. 6 is a vertical cross-section view on line 5-6 of Fig. 4.

Fig. 7 is a detailed view showing in a broken longitudinal verticalsection the level regulator annexed to the continuous clarifier and thelatters connection with the former.

Fig. S is a detailed edge view of an arm agitator used for the liquidsurface with the clariiier.

Fig. 9 is an elevational' detailed View of the same arm agitator.

Fig. l0 is a vertical cross-section detailed view on line lil-l0 of Fig.9.

The method of clarification being an objectof which the liquid iiowsupwardly, impurities deposited above the liquid level being eliminatedand the partial withdrawal of clarified liquid being effected at thelowest Zone of each compartment, in contrast to the clarificationmethods at present known in which the liquid ilows downwardly, the mudis withdrawn at the bottom and the partial removal of clarified liquidis veffected at the upper zone of each compartment.

In the drawings is illustrated a clarifier device for carrying out themethod of this invention, and possibly others, which device consists ofa cylindrical tank l closed at ythe top, the upper portion of which isconical in shape and its bottom portion is in the shape of an invertedcone. The bottom of tank l is provided with a register opening 2 havinga pressure cover 4and a feed-tube 3 for the liquid to be claried, saidfeed-tube 3 ending in .the form of an inverted syphon at a predeterminedheightfrom the bottom, and the bo-ttom of the tank I has also a centralopening and therein a discharge tube 4 provided with a controlling valve5. The tank is divided interiorly into a lower flocculatio-n chamber 6,an' upper sludge discharge chamber l and an intermediate series ofclarifying chambers a, by means of a plurality of annular bailles ortrays 9 of frusto-conical shape or sloping from the center to theperiphery. Said trays are secured at their outer edge to the peripherialwall of tank I and each has an upstanding cylindrical portion 9 at theirupper open portion to permit the liquid to pass upwards along thecentral line of tank I. Each compartment 8 is provided at theperipherial Wall of tank I with a register opening I Il for cleaningpurposes at one side thereof and at the other side each compartment hasa small opening and a discharge tube II provided with a controllingvalve I2 for the liquid claried in the lowest Zone of each compartment.The tray 9 serving as a bottom portion for the sludge upper dischargechamber 1 has a vertical cylindrical portion 9" which is higher than thevertical cylindrical portions 9 of the lower trays and is provided withfour openings I3 near its upper portion which is crossed by a diametralpartition I4 dividing the cylindrical portion in two half portionslaterally opened in a bottom inclined radial conduit I5 (Fig. 4)terminating at .the peripherial wall of tank I in an opening providedwith a discharge tube I6 for the sludge separated from -the liquidsurface. At the upper central portion of the tank I is rotatably mountedon a bearing I1 a vertical shaft I8 supported at its lower end on abearing I9 integral at the middle portion of partition I4. The verticalshaft I8 is provided at its lower end with agitator arms formed byvertical blades 20 in diametral alignment from which other verticalparallel blades 22 are hanging through rings 2|, the vertical shaft I8.being rotated at a very slow speed by means of a horizontal helicoidalwheel 23 actuated by a worm gear 24 coupled Ito the shaft of an electricmotor 25 supported on the upper portion of tank I. The upper portion oftank I has a large opening 26 for connection `with the suction pipe 21communicating with a vacuum condenser which is not shown, formaintaining sub-atmospheric pressure on the surface of the liquid in thetank and at said upper portion of tank I there are also disposed avacuum manometer 28 and a tube with a controlling valve 29 forcommunicating the interior of rtank I with the atmosphere, when desired.

The tubes I I for discharging Vthe claried liquid in the lowest zone ofthe intermediate compartments 8 and the upper chamber 1 are connected tovertical tubes, conduits, or pipes 30 the number of which is equal tothat of tubes I I, lthree of said tubes being indicated in Athedrawings. Said tubes 30, each hold a column of liquid normally inhydraulic communication with the body of liquid l being treated in thetank I, rise up to a predetermined height above the bottom portion of acontrol chamber or closed box 3| supported on a bracket 32 securedexteriorly to .the peripherial wall of tank I, and each tube 30 isprovided withv a controlling valve 30'; On the upper, portions of .thethree .tubes 30 are slidably mounted cylindrical sleeves 33 which lit ontubes 30 and form at their upper ends discharge openings the height ofwhich is adjusted by means of clamps 34 secured to the sleeves 33 andconnected Vto vertical screws 35 threadedly mounted in nuts 36 rotatablymounted on the upper .portion of box 3 I, the object of said threevertically slidable discharge sleeves 33 being to control the dischargeheight of the liquid falling from tubes into an overflow liquidreceiving space outside of `the main wall of the tank I, such as isprovided by box 3I and therefore the level of the liquid within theupper chamber. 1 of tank I. The box 3| is provided with a clarifiedliquid discharge tube 31 leaving from the bottom of the box and leadingdownwards to end in a collector tank (not shown) disposed far beneaththe tank I, said collector -tank being completely sealed to maintain therequired vacuum in the system. The tube 31 has a horizontal branch tube38 connected to the three vertical tubes 30 by means of the horizontaltube 39 and said tube 38 in turn extends to form a vbranch tube benttwice at an angle as indicated by 40 and has a controlling valve 4Ibeneath the bottom of tank I. Through the bottom of tank I two tubes 42each having a controlling Valve 43 extend upwards to be connected at theend of the branch tube 40 and terminate at their upper open end near thetray 9 which serves as a `cover for the ilocculation chamber 6, thefunction of said tubes being to serve as outlets for the clarifiedliquid when the clarifier is emptied for cleaning purposes. The levelcontrolling box 3| is in communication with the vacuum or suction pipe21 through a suction tube 44 having a controlling valve 45 and leadingfrom the upper portion of the box 3 I.

The method of continuous vacuum clarication is carried out by means ofthe described apparatus, as follows: The liquid to be clarified entersthrough feed-tube 3 into the bottom portion of tank I and arises inflocculation chamber G. The iirst occules carried along by the liquid tothe upper edge of. the upstanding cylindrical portion 9 of the lowertray 9 separate from the liquid. Said cylindrical portion 9' and lowertray 9 discharge the liquid and the fioccules into the lowerintermediate compartment 8 wherein additional iloccules separate. Theliquid and the separated lioccules pass into the upper intermediatecompartment 8 and from the latter into the upper chamber 1 wherein theliquid level is regulated by previous adjustment of cylindrical sleeves33 of tubes 30 through suitable action by the screws 35. Agitator arms20-22 are rotated on the surface of the liquid in chamber 1, which sweepthe floccules separated in the various compartments and deposited on thesurface of the liquid within upper chamber I and lead them toward thebottom inclined radial conduit I5 which carries them to discharge tubeI6 through which the sludge separated from the liquid within tank I iswithdrawn. The clarified liquid occupying the lowest zone of eachcompartment 8 and upper chamber 1 by reason of the floccules tending toarise on account of their buoyed up condition, is withdrawn throughtubes I I and discharged through vertical tubes 30 within the box 3l andiinally collected through vertical tube 31 in the aforesaid collectortank (not shown).

The tank I, box 3| and clarified liquid collector l tank being sealed,the system operates at a pressure below atmospherical pressure,preferably at a pressure of 35 mms., and a difference of 3 C. intemperature is used below the temperature corresponding to the vacuumpressure in the apparatus in order to avoid treatment of the liquid at atemperature sometimes above 216 F. at which the continuous claricationoperation must be performed under the processes and apparatus at presentused. My vacuum process and apparatus eliminate the losses of sucrose oninversion which at present occur as caused by heat and the increase ofdarkness of color of Syrups due to the candied condition attained bysucrose, thereby causing the use of a larger amount'of decoloring agentsin the decoloring operation in order to obtain the so-called No. 1liquor and the production of a greater percentage of molasses in thecrystallization operation in which reiined sugar is obtained. f

It is obvious that the operating details of the method, the character ofthe liquid suspension treated, and the construction details of theapparatus for carrying it out can be varied within certain limitswithout thereby affecting the essential characterA of the inventionLwithin the scope of the appended claims.

What I claim is:

1. An apparatus for continuous clarification, comprising a cylindricaltank divided by means of trays of frustro-conical shape sloping from themiddle portion to the periphery in an upper chamber for sludgeseparation, a lower liquid en tering and initial occulation chamber, anda plurality of intermediate compartments for additional claricationupwards, a ieed tube for the liquid to be clarified in the lowerchamber, said trays having a large opening at the center or their upperportion from the edge of which rises a cylindrical tube, a sludgedischarge tube above the liquid level in the upper chamber means formaintaining reduced pressure in the tank, land tubes for withdrawal ofclariiied liquid at a point of the lowest Zone or each compartment.

2. An apparatus for continuous clarification, comprising a cylindricaltank divided by means of circular trays of frustro-ccnical shape slopingfrom the middle portion to the periphery in an upper sludge separationchamber, a lower chamber for liquid entrance and initial ilocculationand intermediate compartments for additional clarification upwards, afeed tube for the liquid to be clariiied in the lower chamber, saidtrays having a large 'opening at the center of their upper portion fromthe edge of which rises a cylindrical tube, agitator arms rotatablymounted on a vertical shaft in the upper chamber at a level adjacent theliquid surface, means for `maintaining reduced pressure in the tank, aradial conduit having an inclined bottom portion situated beneath theagitator arms to receive the sludge gathered on the liquid surface, asludge discharge tube connected to the tank wall at the end of theradial conduit, and tubes for withdrawing claried liquid at a point ofthe lowest zone of each compartment.

3. An apparatus for continuous clarification, comprising a cylindricaltank divided by means of circular trays of frusto-conical shape slopingfrom the middle portion to the periphery in an upper sludge separationchamber, a lower chamber for liquid entrance and initial flocculationand intermediate compartments for additional clarication upwards, saidtrays having a large opening at the center of their upper portion fromthe edges of which rises a cylindrical portion which does not reach theimmediate upper tray, a feed tube for the liquid to be clarified in thelower chamber, which tube ends in the shape of an inverted syphon at apredetermined height above the tank bottom, agitator arms rotatablymounted on a vertical shaft in the upper charnber at a level adjacentthe liquid surface, a radial conduit having an inclined bottom portionsituated beneath the agitator arms to receive the sludge gathered on theliquid surface, a sludge discharge tube connected to the tank wall atthe end of the radial conduit, tubes for withdrawal of clarified liquidat a point of the lowest zone of each intermediate compartment and upperchamber,l means for maintaining reduced pres- 6 i sure in the tank andouter means for regulating the surface level of the liquid within thetank, said means consisting of a box enclosing the upper portions of theclariiied liquid withdrawal tubes and cylindrical sleeves slidablyadjusted on the discharge openings of the withdrawal tubes forregulating the discharge :tall height within the box.

4. Apparatus for continuous operation on liquid suspensions, comprisinga sealed casing arrangement for holding an ever-changing body of liquidbeing treated, annular baie means having an inclined face separatingsuch casing arrangement into liquid communicating compartments, meansfor applying suction to the interior of the casing for maintainingsub-atmospheric pressure on liquid therein, means for controlling theelevation of the liquid level in the casing, means for withdrawingfloating material from such liquid level, means for conductingfeed-liquid through the bottom section of the casing to the region ofsuch level, and means including a conduit passing through the casing andleading from an elevation substantially below such level for withdrawingdownwardly descending clarified liquid from at least one of thecompartments through a liquidconducting passage located functionallyremote from such level and adjacent the bottom of that compartment.

5. Apparatus for continuous operation on liquid suspensions, comprisinga sealed tank adapted to hold an ever-changing body of liquid beingtreated, means for applying suction to the inte 1icr of the tank formaintaining sub-atmospheric pressure on liquid therein, means forwithdrawing floating material from the liquid level in the tank, meansfor conducting 4feed-liquid through the bottom section of the tank andrisingly to the region of such level, substantially annular baille meansextending to an elevation below such level in the tank and so disposedas to encircle the conducted feed-liquid but with one side thereoffacing such feed-liquid and with one side thereof facing away from suchfeed-liquid, and means for passing downwardly descended clarified liquidto discharge from the tank including conduit means passing through thetank as well as leading from an elevation below such level and from thatside of the baffle means facing away from such feed-liquid.

6. Apparatus according to claim 5, with the addition of a chamberextending beyond the tank but subject to subatmospheric pressure forholding under such sub-pressure a column of clarified efiluent liquidpassed from the tank to the cham ber, said conduit means leading fromthe tank to the chamber, and means for discharging liquid from thechamber to the atmosphere.

7. Apparatus according to claim 5, with the addition of a chamberextending beyond the tank but subject to such sub-atmospheric pressurefor holding under such sub-pressure a column of upflowing clarifiedeffluent liquid passed from the tank to the chamber, said conduit meansleading from the tank to the chamber, means for discharging liquid fromthe chamber to the atmosphere, adjustable means associated with thechamber operative upon the eiiiuent liquid delivered through saidconduit means for controlling the liquid level therein, and meansextending to a place of atmospheric pressure for adjusting theadjustable means.

JOS RAMN osUNA.

